The present invention relates generally to fluorescent monomers. In another aspect, this invention relates to tagged treatment polymers that contain these fluorescent monomers. In a further aspect, this invention relates to the use of tagged treatment polymers containing fluorescent monomer(s) therein in industrial water systems.
In many industrial water systems that employ polymers as water treatment agents it may be desirable to tag or mark such polymers to facilitate monitoring thereof. By the term “monitoring” is meant herein any type of tracing or tracking to determine the location or route of the polymers, and any type of determination of the concentration or amount of the polymer at any given site, including singular or intermittent or continuous monitoring. For instance, it may be desirable to monitor water treatment polymers in water systems, or to monitor polymers that may be present in waste fluids before disposal, or to monitor the polymer used in fluids for down-hole oil well applications, or to monitor polymers that may be present in fluids used to wash a manufactured product.
As seen from the above list of possible applications of polymer monitoring, the purpose of such monitoring may be to trace or track or determine the level of the polymer itself, or to trace or track or determine the level of some substance in association with the polymer, or to determine some property of the polymer or substance in association with the polymer, for instance its leachability.
There are many industrial water systems. Because water resources are becoming limited and efficient utilization of water is required, various methods have been adopted to reduce the amount of water used in all industrial water systems. As the methods for reducing the amount of water are put into practice, unfavorable events can occur. These unfavorable events occur because the quality of the water in the system is progressively deteriorated. These unfavorable events can include the formation of scale.
To prevent or minimize unfavorable events, various kinds of treatment agents for treatment of water systems have been used. It has been found that organic substances, including certain types of treatment polymers, are effective for preventing formation of scale. These certain types of treatment polymers are known to persons of ordinary skill in the art of industrial water treatment and are widely used by themselves or as one of many possible components in scale inhibition products.
When a treatment polymer is used for preventing formation of scale the concentration of the treatment polymer in the water system is the important factor so that the treatment polymer performs the desired function with good efficiency. For example, a treatment polymer added to a cooling water system can be consumed by many causes. With consumption, the amount of the treatment polymer dissolved in the cooling water does not remain the same as the amount added to the cooling water. Therefore, it is important for the optimum operation of an industrial water system that practical methods are known to determine the concentration of treatment polymers in the water of the industrial water system.
In general practice, the amount of the treatment polymer added to the water in an industrial water system can be measured using various analytical methods. The use of an inert fluorescent tracer or mass balance measurement method as described in U.S. Pat. Nos. 4,783,314; 4,992,380; and 5,171,450, hereby incorporated by reference; to perform this analysis is known in the art.
In the inert fluorescent tracer method, an inert fluorescent tracer is added to an industrial water system, with the amount of inert fluorescent tracer added being proportional to the amount of the treatment polymer added. By using a fluorometer to measure the fluorescent signal of the inert fluorescent tracer, the amount of the inert fluorescent tracer can be determined by using a calibration curve to relate the amount of fluorescent signal detected to the amount of the inert fluorescent tracer present. Because the inert fluorescent tracer and the treatment polymer are added to the industrial water system in known proportions, by knowing the amount of inert fluorescent tracer present it also means that the amount of treatment polymer present is known.
The inert fluorescent tracer method can be conducted on-line and in real time so that any changes in the amount of treatment polymer being added to the system can be made immediately. As a complement to the use of an inert tracer system, it has been found that treatment polymers that are used as components of scale inhibitors in industrial water systems could be monitored if tagged with a fluorescent monomer. The amount of fluorescent monomer incorporated into the tagged treatment polymer must be enough so that the fluorescence of the tagged treatment polymer can be adequately measured; however, it must not be so much that the performance of the tagged treatment polymer as a treatment agent for the water is decreased. Because the concentration of the tagged treatment polymer itself can be determined using a fluorometer, it is now possible to measure consumption of the tagged treatment polymer directly. It is important to be able to measure consumption directly because consumption of a treatment polymer usually indicates that a non-desired event, such as scaling, is occurring. Thus, by being able to measure consumption of the tagged treatment polymer, there can be achieved an on-line, real time, in-situ measurement of scaling activity in the cooling system.
There are a number of florescence measuring processes and tagged polymer process known in the art. Some examples are described in U.S. Pat. Nos. 5,986,030, 6,312,644, 6,645,428, 7,148,351, 7,601,789, 7,875,720, 6,358,746, 3,888,863, 3,310,564, 3,845,075, and 4,377,703, International Published Patent Applications: WO 2011/036075 A1 and WO2008/001036 A2, Canadian Patent Document CA 884330 A, United Kingdom Patent Documents: GB 1,378,880, GB 1,518,855, GB 1,392,253, GB 1,384,821, GB 1,095,784, GB 1,345,176 and scientific papers: Synthesis of a Novel Oxoxanthenoisoquinoline via a Palladium-Catalysed Cross-Coupling Reaction; as a Fluorophore, by Mark P Prickett et al., Tetrahedron Letters, Vol. 41, Issue 16, pp. 2987-2990 (2000) and Benzo[k, l], Xanthene-3,4-Dicarboximides and Benzimidazoxanthenoisoquinolinones—Yellow and Orange Dyes for Synthetic-Polymer Fibres, by A T Peters et al., Journal of the Society of Dyers and Colourists, Vol. 105, issue 1, pp. 29-35 (1989). However, there are few viable tagged treatment polymers for use as treatment polymers in industrial water systems. Therefore, it is desirable to produce additional tagged treatment polymers that have a fluorescent signal so that a fluorometer can be used to measure the fluorescent signal of the tagged treatment polymer and determine the concentration of tagged treatment polymer currently present in the industrial water system from that information.
It is known that tagging of polymers is difficult to accomplish because of the difficulty in chemically combining fluorescent moieties with non-fluorescent polymers. Therefore, in order to synthesize tagged treatment polymers it is also desirable to produce fluorescent monomers that are readily polymerized to form tagged treatment polymers.
Thus it is clear that there is definite utility in novel methods and compositions for making and using tagged treatment polymers. The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “Prior Art” with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 CFR §1.56(a) exists.